New condition old stock manufactured by Tom Bowers of subguns.com fame.  All stainless steel design including tube, endcaps and baffles with laser engraved marking.  Endcaps cannot be removed for cleaning or disassembly.  Available in either 1/2x28 thread or 1/2x20 thread.  Size is approx. 1" OD x 6" long.  Only one of each thread pitch in stock.  Call to order.